Proteinuria Unrelated to Pregnancy-Induced Hypertension: More than 1200mg in 24 hours is Associated with Renal Disease and Adverse Pregnancy Outcomes

Background: Proteinuria during pregnancy in women without pregnancy-induced hypertension (PIH) may be physiological. The relationship between the magnitude of proteinuria and obstetric outcomes in women without PIH is unclear. Materials and Methods: This retrospective cohort study was conducted at the obstetric wards of a teaching hospital in South India. Women without PIH were included and those with proteinuria were compared to those without proteinuria. Data were collected from the hospital records on maternal and fetal outcomes and the causes of proteinuria. Results: Most women with proteinuria were diagnosed during the second trimester and had more previous live births and abortions and higher blood pressures compared to those without. Women with proteinuria had similar maternal outcomes but a higher rate of adverse fetal outcomes (31.6% vs. 11.7%) than those without proteinuria. More than 1.2 g proteinuria in 24 h was associated with a diagnosis of renal disease and 1.5 g of protein in a 24-h urine sample was associated with worse fetal outcomes. Pregnant women with lower levels of proteinuria unrelated to preeclampsia had similar outcomes to patients without proteinuria. Conclusion: In this cohort, a higher level of proteinuria was associated with worse fetal outcomes and renal disease with optimum cutoffs of 1.5 g and 1.2 g, respectively. Larger prospective cohorts are required for more definitive conclusions.